I have a Co-Pilot in Steel Dyneema. I got it to use as a computer bag. One that can carry a quart-size water bottle.
And it works! My Sony Vaio Z is officially 12-2/5" wide, and it fits just fine in the Co-Pilot's main compartment. For quite a while I just put it in "unprotected," and was careful with the bag -- and it was fine, even when traveling.
I've since gotten a Waterfield "13 inch MacBook Pro" Suede Jacket -- the Ultrasuede sleeve that's only padded on the bottom, which is really only where I needed it for this use. And the computer and sleeve still fit inside the Co-Pilot, though it's a tad tight (the sleeve probably increases the width to about 12-5/8").
Been using it now as my everyday computer bag for 7 months and my computer is still just fine.
Oh, and the accessories -- charger, wireless mouse, earbuds -- fit just fine in the main compartment's pockets along with the computer.
Conclusion: If you're traveling with a Vaio Z, or perhaps a MacBook (which seems to be about the same size), and you're willing to take a bit of care, the Co-Pilot *will* fit your computer and work well as a computer bag.
I do think it might be nice if it were 13" instead of 12"...then it would fit a neoprene computer case. I think a lot of Tom Bihn customers have 13" MacBook Pros (or Vaio Zs).
ETA pictures, packed pretty much as it was last time I traveled.
Without Suede Jacket:
With Suede Jacket:
Everything that was in it (and one side pocket was still almost empty):